2.1.2.6 Comparison operators

So far, we have learned how to move values around between the MIX
registers and its memory cells, and also how to perform arithmetic
operations using these values. But, in order to write non-trivial
programs, other functionalities are needed. One of the most common is
the ability to compare two values, which, combined with jumps, will
allow the execution of conditional statements.
The following instructions compare the value of a register with ‘V’, and
set the CM indicator to the result of the comparison (i.e. to
‘E’, ‘G’ or ‘L’, equal, greater or lesser respectively).

CMPA

Compare [rA] with V. OPCODE = 56, MOD = fspec.

CMPX

Compare [rX] with V. OPCODE = 63, MOD = fspec.

CMPi

Compare [rIi] with V. OPCODE = 56 + i, MOD = fspec.

As explained above, these instructions modify the value of the MIX
comparison indicator; but maybe you are asking yourself how do you use
this value: enter jump operators, in the next subsection.